Brake-shoe.



C. D. PETTIS.

BRAKE SHOE. APPLICATION FILED AUG.20'. 1914.

1,1 38,784, Patent-ed May 11, 1915.

CLIFTON D. PETTIS, RIDGEWOOD, NEW JERSEY.

BRAKE-SHOE.

Specification of Letters Patent.

Patented May 11, 1915.

Application filed August 20, 1914. Serial No. 857,632.

T all wlzom it may concern:

Be it known that I, CLIFTON D. PETTIS, a

citizen of the United States, residing at in Letters Patent No. 1,100,093 and No.-

1,100,094 granted to me under date of June 16, 1914.

In the accompanying drawings Figure 1 is a side view of a brake shoe embodying my invention. Fig. 2 is a back plan view of the shoe, a portion of the ductile metal back being broken away. Fig. 3 is a plan view of the ductile metal back. Fig. 4 is a detail sectional view of a portion of the ductile metal back on line 44 of Fig. 3, this view being upon an enlarged scale. The body 10 of my improved brake shoe is formed of cast metal that is united to the back 11 of ductile metal and preferably of pan-shape, in the casting operation. In the accompanying drawing the back 11 of the shoe is shown of the shape illustrated in Letters Patent Numbers 1,100,092 and 1,100,093 granted to me June 16, 1914, the end portions of the back 11 being formed with L-shaped openings 12 as shown in Patent No. 1,100,093, while the central portion of the shell or back 11 is formed with openings 13 corresponding with the openings shown in Patent 1,100,092 of June 16, 1914. The purpose of the openings 12 of the back or shell 11 is to receive prongs or projections 15 and 16 that form the end lugs of the brake shoe as in my Patent No. 1,100,093 and the purpose of the openings 13 about the center of the back or shell 11 is to receive prongs or projections 14 that unite with the center lug 20 as in my Patent No. 1,100,092 of June 16, 1914. The prongs or projections 14, 15 and 16 eX- tend from a supplemental ductile metal reinforcing member 21 that is located within the back or shell 11 as in my hereinbefore mentioned Letters Patent.

The main object of my present invention is to provide a brake shoe with a ductile metal back of such character that when the cast metal that is to form the body of the shoe is poured into the back or shell a free escape of air and gases may occur thus avoiding the danger of forming blowholes in the body of the shoe which would tend to weaken the body and prevent its firm union with the ductile metal back in the castlng operation. To this end my invention consists primarily in providing the back or shell with a plurality of small perforations of such size as that in the operation of casting the body of the shoe, these perforations will permit the free escape of air or gas but will check the flow of metal through the back or shell. 4

When .a reinforcing member 21 is employed, the perforations 25 in the back or shell 11 will be formed therein at points opposite the reduced or cut-away portions of said reinforcing member 21. These perforations 25 will be made in any desired number and shape, but the preferably perforations are from 1/64th to 1/32nd of an inch in size, as in practice it is found that this size of perforations will efiectively serve to permit the escape of air or gas in the operation of casting the body of the shoe while preventing the fiow of the metal through the perforations. The size of the perforations may vary in accordance with the character and fluidity of the metal of which the body of the brake shoe is formed.

The back or shell 11 of the shoe is shown as formed with a single pouring-hole 26 through which the cast metal that is to form the body of the shoe will be poured. The reinforcing member 21 is shown as formed with reduced or cut-away portions adjacent its center and one or more openings 22, one of which will come opposite the pouring hole 26 of the back or shell. When the back or shell 11 with reinforcing member 21 therein has been placed in the mold, the hole 26 will come opposite the pouring opening of the mold and as the cast metal is poured into the mold, the air and gas will escape freely through the perforations 25 at difi'erout parts of the back or shell 11, avoiding the formation of blow-holes and permitting the cast metal to firmly unite with the surface of the back or shell 11 and with reinforcing ductile metal 21.

. Preferably the perforations 25 are formed by punching inward (and without cutting a y) t e thin metal of back r shell- This punching inward of the metal to form the perforations leaves slight burs or projections 27 around the perforations 25, which although not essential aid in effecting a more secure union between the cast metal body and the ductile metal back or shell. Manifcstly, however, the perforations 25 might be formed by cutting or punching away small parts of the back or shell, but

this would be a more expensive operation.

Having thus described my invention, What I claim as new and desire to secure by Letters Patent is:

' 1. A brake shoe comprising a cast metal body and a ductile metal back provided With a plurality of perforations of such size as to permit the escape of air but check the flow of metal through the back in the casting operation.

2. A brake shoe comprising a cast metal body and a ductile metal back provided With a plurality of perforations of such size as to permit the escape of air but check the flow of metal through the back in the casting operation, said perforations having inwardly projecting edges.

3. A brake shoe comprising a cast metal body, a ductile metal back, a reinforcing member Within said back, said back being provided With a plurality of perforations of such size as to permit the escape of air but check the flow of metal through the back in the casting operation.

4:. A brake shoe comprising a cast metal body, a ductile metal back and a reinforcing member Within said back and having re duced or cut-away portions, said ductile metal back being provided at points opposite the cut-aWay portions of said reinforcing member, with perforations of such size 40 as to permit the escape and flow of air.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

- Washington, D. O. 

